This invention relates to throttle control systems for motor vehicles and more particularly to an electronic throttle control system.
Conventionally, throttle control systems for motor vehicles have consisted of a throttle pedal connected to a cable which in turn is connected to the throttle body of the engine so as to control the throttle valve mounted within the throttle body and thereby control the delivery of the fuel/air mixture to the engine. Whereas cable controlled throttle control systems are generally satisfactory and have seen widespread application, they present problems in the context of the increasingly crowded underhood environment of a modern day motor vehicle. Specifically, the cables must be circuitously routed from the accelerator pedal to the throttle body and the resulting circuitous configuration of the cable creates large amounts of friction within the cable assembly and thereby renders the cable assembly relatively inefficient. The prior art cable systems have also often failed to provide the required sensitivity as between movement of the throttle pedal and the desired movement of the throttle valve of the throttle body.
In an effort to avoid the disadvantages of the cable controlled systems, electronic systems have been developed to transmit the signal from the accelerator pedal to the throttle valve. However, the prior art electronic control systems have failed to provide a smooth control signal but rather have provided an oscillating control signal which has had the effect of inducing shock loading and damage to the transmission and other drivetrain components.